89S52模拟键盘，并可以接外接大键盘，适合工控场合使用，相当于常规键盘的缩水版-89S52 analog keyboard, and can access external large keyboard, suitable for industrial control occasions, equivalent to conventional keyboard shrunk version

基于C8051F330的交—交变频控制系统程序，包含变频控制键盘值读取已经显示。-Based C8051F330 AC- AC variable frequency control system program, including frequency control the keyboard value read has shown.